Field of the Invention: The present invention relates to a process for preparing cationic resins, to aqueous dispersions of the cationic resins, and to the use of these dispersions in cationic electrodeposition.
Brief Description of the Prior Art: Cationic electrodeposition resins are well known in the art. For example, U.S. Pat. No. 4,104,147 to Jerabek et al discloses cationic electrodepositable resins which are formed from reacting a polyepoxide with a primary or secondary amine and solubilizing the polyepoxide-amine adduct in aqueous medium with the aid of acid. The polyepoxide is contacted and heated with a polymeric polyol, for example, a polyester polyol such as a polycaprolactone diol or a polyether polyol such as polyoxytetramethylene glycol before reaction with the primary or secondary amine.
U.S. Pat. No. 3,839,252 discloses quaternary ammonium salt group-containing resins which are formed from reacting a polyepoxide with a tertiary amine salt. The polyepoxides are optionally contacted and heated with a polyether polyol such as polyoxypropylene glycol or polyoxyethylene glycol before reaction with the tertiary amine salt.
U.S. Pat. No. 4,260,720 discloses cationic electrodepositable resins which are derived from a polymercapto-chain extended polyepoxide. Among the polyepoxides which may be used are polyglycidyl ethers of cyclic polyols such as bisphenol A and 1,2-bis(hydroxymethyl)cyclohexane. These polyepoxides can be produced by etherification of the cyclic polyol with epichlorohydrin in the presence of alkali. Besides bisphenol A and 1,2-bis(hydroxymethyl)cyclohexane, oxyalkylated adducts of these cyclic polyols such as ethylene oxide and propylene oxide adducts can be used.